WO2021220838A1

WO2021220838A1 - Organic electroluminescence element material and organic electroluminescence element

Info

Publication number: WO2021220838A1
Application number: PCT/JP2021/015655
Authority: WO
Inventors: 裕士池永; 孝弘甲斐; 和成吉田; 健太郎林
Original assignee: 日鉄ケミカル＆マテリアル株式会社
Priority date: 2020-04-30
Filing date: 2021-04-16
Publication date: 2021-11-04
Also published as: TW202200754A; JPWO2021220838A1; KR20230005838A; EP4144817A1; CN115443552A; US20230128732A1

Abstract

Provided are: an organic EL element that has high efficiency and a long lifespan while having a low driving voltage; and an organic electroluminescence element material suitable for same. This organic electroluminescence element material comprises an indolocarbazole compound represented by general formula (1). Here, ring A represents a heterocyclic ring represented by formula (1a), Ar¹ and Ar² are each an aromatic hydrocarbon group, an aromatic heterocyclic group or a linked aromatic group, L² represents an aromatic heterocyclic group, Ar³ represents an aromatic hydrocarbon group or a linked aromatic group in which a plurality of said aromatic hydrocarbon groups are linked together, and a+b+c≥1 is satisfied.

Description

Materials for organic electroluminescent devices and organic electroluminescent devices

The present invention relates to a material for an organic electroluminescent device and an organic electroluminescent device using the same.

By applying a voltage to an organic electroluminescent element (referred to as an organic EL element), holes are injected into the light emitting layer from the anode and electrons are injected from the cathode into the light emitting layer. Then, in the light emitting layer, the injected holes and electrons are recombined to generate excitons. At this time, singlet excitons and triplet excitons are generated at a ratio of 1: 3 according to the statistical law of electron spin. It is said that the internal quantum efficiency of a fluorescent light emitting type organic EL device that uses light emission by a singlet exciton is limited to 25%. On the other hand, it is known that the phosphorescent organic EL element that uses light emission by triplet excitons can increase the internal quantum efficiency to 100% when intersystem crossing is efficiently performed from the singlet excitons. Has been done.
However, extending the life of a phosphorescent organic EL device has become a technical issue.

More recently, highly efficient organic EL devices using delayed fluorescence have been developed. For example, Patent Document 1 discloses an organic EL device using a TTF (Triplet-Triplet Fusion) mechanism, which is one of the delayed fluorescence mechanisms. The TTF mechanism utilizes the phenomenon that singlet excitons are generated by the collision of two triplet excitons, and it is theoretically thought that the internal quantum efficiency can be increased to 40%. However, since the efficiency is lower than that of the phosphorescent type organic EL device, further improvement in efficiency is required.
On the other hand, Patent Document 2 discloses an organic EL device using a TADF (Thermally Activated Delayed Fluorescence) mechanism. The TADF mechanism utilizes the phenomenon that inverse intersystem crossing from a triplet exciter to a singlet exciter occurs in a material with a small energy difference between the singlet level and the triplet level, and theoretically determines the internal quantum efficiency. It is believed that it can be increased to 100%. However, as with the phosphorescent element, further improvement in life characteristics is required.

WO 2010/134350 A WO 2011/070963 A WO 2008/056746 A Japanese Patent Application Laid-Open No. 2003-133075 WO 2013/062075 A US 2014/0374728 A US 2014/0197386 A US 2015/0001488 A WO 2011/136755 A KR 2013/132226 A WO 2016/042997 A

Patent Documents 3 and 10 disclose the use of indolocarbazole compounds as host materials. Patent Document 4 discloses the use of a biscarbazole compound as a host material.

Patent Documents

5 and 6 disclose that a biscarbazole compound is used as a mixed host. Patent Documents 7 and 8 disclose that an indolocarbazole compound and a biscarbazole compound are used as a mixed host.

Patent Document 9 discloses the use of a host material in which a plurality of hosts containing an indolocarbazole compound are premixed.

Patent Document 11 discloses the use of a host material in which a plurality of indolocarbazole compounds are premixed.
However, none of them can be said to be sufficient, and further improvement is desired.

In order to apply an organic EL element to a display element such as a flat panel display, it is necessary to improve the luminous efficiency of the element and at the same time to sufficiently secure the long life characteristics of the element. In view of the above situation, it is an object of the present invention to provide a practically useful organic EL device having high efficiency and long life while having a low drive voltage, and a compound suitable for the organic EL device.

As a result of diligent studies, the present inventors have found that the condensed aromatic heterocyclic compound represented by the following general formula (1) exhibits excellent properties when used in an organic EL element, and completed the present invention. I arrived.

The present invention is a material for an organic electroluminescent device composed of a compound represented by the general formula (1).

Here, the ring A is a heterocyclic ring represented by the formula (1a), and the ring A is fused with an adjacent ring at an arbitrary position, and Ar ^{1 is} independently substituted or unsubstituted and has 6 to 30 carbon atoms. Indicates an aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group having 3 to 11 carbon atoms, or a substituted or unsubstituted linked aromatic group formed by linking 2 to 5 of these aromatic rings. Ar ² independently has an substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or two aromatic rings thereof. Indicates a substituted or unsubstituted linked aromatic group consisting of up to 5 linked aromatic group, and L ¹ is independently substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or substituted or unsubstituted carbon number. It is an aromatic heterocyclic group ^{having 3 to 11, L 2} represents an aromatic heterocyclic group having 3 to 11 substituted or unsubstituted carbon atoms, and Ar ³ is an independently substituted or unsubstituted aromatic heterocyclic group having 6 to 11 carbon atoms. It represents 30 aromatic hydrocarbon groups, or substituted or unsubstituted linked aromatic groups in which 2 to 5 of these aromatic hydrocarbon groups are linked, and a and b each independently indicate an integer of 0 to 4. , C represent an integer of 0 to 2. However, a + b + c ≧ 1. d represents the number of repetitions and independently represents an integer of 0 to 3, e represents the number of substitutions and represents an integer of 0 to 5.

The compound represented by the general formula (1) can be a nitrogen-containing aromatic group having ^{L 2 having 3 to 5 carbon atoms.} Further, Ar ¹ , Ar ² , and L ¹ are aromatic hydrocarbon groups having 6 to 24 carbon atoms, or substituted or unsubstituted linked aromatic groups in which 2 to 5 aromatic hydrocarbon groups are linked. There can be, preferably d = 0.

The compound represented by the general formula (1) is preferably a compound represented by any of the formulas (2) to (7).

Here, L ² , Ar ¹ , Ar ² , Ar ³ , a, b, c and e agree with the above general formula (1).

In the general formula (1) or the formulas (2) to (7), at least one of a and b is 0, and c ≧ 1.

Further, the present invention is an organic electroluminescent element having a plurality of organic layers between an anode and a cathode, and at least one of the organic layers is an organic layer containing the above-mentioned material for an organic electroluminescent element. It is an organic electroluminescent element characterized by.

The organic layer containing the above-mentioned material for an organic electroluminescent device may contain at least one of the material for an organic electroluminescent device and the compounds represented by the general formulas (8) to (10).

Here, Ar ⁴ and Ar ⁵ are independently substituted or unsubstituted aromatic hydrocarbon groups having 6 to 30 carbon atoms, substituted or unsubstituted aromatic heterocyclic groups having 3 to 17 carbon atoms, or these. Indicates a substituted or unsubstituted linked aromatic group formed by linking 2 to 5 aromatic rings.

Here, ring B is a heterocycle represented by the formula (9b) or (9c), ring B is condensed with an adjacent ring at an arbitrary position, and L ³ is an independently substituted or unsubstituted carbon number. It is an aromatic hydrocarbon group of 6 to 30, where X represents NA ⁸ , O, or S.
Ar ⁶ , Ar ⁷ , and Ar ⁸ are independently substituted or unsubstituted aromatic hydrocarbon groups having 6 to 30 carbon atoms, substituted or unsubstituted aromatic heterocyclic groups having 3 to 17 carbon atoms, or Indicates a substituted or unsubstituted linked aromatic group formed by linking these aromatic rings 2 to 5. i and j each independently represent an integer of 0 to 3, k and v represent the number of substitutions, k represents 0 to 3, and v independently represents an integer of 0 to 4. However, i + j is an integer of 1 or more.
R ¹ to R ³ are independently cyano groups, alkyl groups having 1 to 20 carbon atoms, aralkyl groups having 7 to 38 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, alkynyl groups having 2 to 20 carbon atoms, and carbon atoms. A dialkylamino group having 2 to 40 carbon atoms, a diarylamino group having 12 to 44 carbon atoms, a dialalkylamino group having 14 to 76 carbon atoms, an acyl group having 2 to 20 carbon atoms, an acyloxy group having 2 to 20 carbon atoms, and a carbon number of carbon atoms. 1 to 20 alkoxy groups, 2 to 20 carbons alkoxycarbonyl groups, 2 to 20 carbons alkoxycarbonyloxy groups, 1 to 20 carbons alkylsulfonyl groups, substituted or unsubstituted aromatics with 6 to 30 carbon atoms It may represent a group hydrocarbon group or an aromatic heterocyclic group having 3 to 17 carbon atoms substituted or unsubstituted, and each of them may have a substituent. f and h independently represent an integer of 0 to 4, and g represents an integer of 0 to 2.

Here, the rings D and D'are heterocycles represented by the formula (10d), and the rings D and D'are independently fused with the adjacent rings at arbitrary positions.
Ar ⁹ independently agrees with ^{Ar 6} of the above general formula (9) ^{, R 4} to R ⁶ independently ^{agree with R 1} to R ³ , and l and n independently agree with 0 to 4, respectively. Indicates an integer of, and m independently indicates an integer of 0 to 2. Ar ¹⁰ is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a substituted or substituted product formed by linking 2 to 5 of them. Represents an unsubstituted linked aromatic group.

The organic layer can be at least one layer selected from a group consisting of a light emitting layer, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a hole blocking layer and an electron blocking layer. A light emitting layer is preferable. This light emitting layer contains at least one kind of light emitting dopant.

Further, the present invention is a mixed composition containing a compound represented by the general formula (1) and a compound represented by the general formula (8), the general formula (9), or the general formula (10). It is desirable that the difference in their 50% weight loss temperatures is within 20 ° C.

The present invention is also a method for manufacturing an organic electroluminescent device, which comprises forming a light emitting layer using the above mixed composition.

Since the material for an organic EL element of the present invention has an aromatic hydrocarbon group on a condensed aromatic heterocycle, the hole injection transportability of the material can be improved to a high level by appropriately designing the number of substitutions and the connection mode. It is assumed that it could be controlled by.
In addition, it is presumed that the electron injection transportability of the material could be controlled at a high level by changing the type of the substituent bonded to ^{L 2 and the position where the substituent was introduced.}
Since it has the above characteristics, the material of the present invention is a material having both charge (electron / hole) injection transportability suitable for the device configuration, and the device can be driven by using this for an organic EL device. It is considered that unexpected characteristics such as voltage reduction and high luminous efficiency could be achieved.
Further, since it is assumed that the material for an organic EL device of the present invention exhibits good amorphous characteristics and high thermal stability and at the same time is extremely stable in an excited state, the organic EL device using this is unexpectedly long. It has a long life and is considered to have shown a practical level of durability.

It is sectional drawing which shows one structural example of an organic EL element.

The material for an organic electroluminescent device of the present invention is represented by the general formula (1). In the general formula (1), the ring A is a heterocycle represented by the formula (1a), and the ring A is condensed with an adjacent ring at an arbitrary position.

Ar ¹ independently contains a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 11 carbon atoms, or 2 to 5 of these aromatic rings. Indicates a substituted or unsubstituted linked aromatic group formed by linking, preferably a substituted or unsubstituted aromatic hydrocarbon group having 6 to 24 carbon atoms, or 2 to 5 of these aromatic hydrocarbon groups. It is a linked substituted or unsubstituted linked aromatic group, more preferably a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or 2 to 5 of these aromatic hydrocarbon groups. It is a linked substituted or unsubstituted linked aromatic group formed by linking.

Ar ² independently has a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or 2 to 2 to these aromatic rings. Shows 5 linked substituted or unsubstituted linked aromatic groups, preferably 2 to 5 substituted or unsubstituted aromatic hydrocarbon groups having 6 to 24 carbon atoms or aromatic hydrocarbon groups. It is a substituted or unsubstituted linked aromatic group, more preferably a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or 2 to 5 of these aromatic hydrocarbon groups are linked. It is a substituted or unsubstituted linked aromatic group.

Specific examples of cases where Ar ¹ and Ar ² are an unsubstituted aromatic hydrocarbon group, an aromatic heterocyclic group, or a linked aromatic group include benzene, naphthalene, acenaphthene, acenaphthylene, azulene, anthracene, chrysene, and pyrene. , Phenantren, triphenylene, fluorene, benzo [a] anthracene, tetracene, pentacene, hexacene, coronen, heptacente, pyridine, pyrimidine, triazine, thiophene, isothiazole, thiazole, pyridazine, pyrrole, pyrazole, imidazole, triazole, thiadiazol, pyrazine, Fran, isoxazole, quinoline, isoquinoline, quinoxalin, quinazoline, thiasiazol, phthalazine, tetrazole, indol, benzofuran, benzothiophene, benzoxazole, benzothiazole, indazole, benzimidazole, benzotriazole, benzoisothiazole, benzothiazol, purine, pyranone, Examples thereof include coumarin, isocmarin, chromone, dibenzofuran, dibenzothiophene, dibenzoselenophen, carbazole, or a group formed by taking one hydrogen from a compound composed of 2 to 5 linkages thereof. Preferably, benzene, naphthalene, acenaphthene, acenaphthylene, azulene, anthracene, chrysene, pyrene, phenanthrene, triphenylene, fluorene, benzo [a] anthracene, tetracene, pentacene, hexacene, coronene, heptacene, or a combination of 2 to 5 of these. Examples include groups resulting from the constituent compounds. More preferably, it results from benzene, naphthalene, acenaphthene, acenaphthylene, azulene, anthracene, chrysene, pyrene, phenanthrene, triphenylene, fluorene, benzo [a] anthracene, tetracene, or a compound composed of 2-5 linkages thereof. The group is mentioned. More preferably, it is a phenyl group, a biphenyl group, or a terphenyl group. The terphenyl group may be linearly linked or branched.
When Ar ¹ is an aromatic heterocyclic group, it is limited to an aromatic heterocyclic group having 3 to 11 carbon atoms. Therefore, dibenzofuran, dibenzothiophene, dibenzoselenophene and carbazole are excluded from the above. Preferred unsubstituted aromatic heterocyclic groups include groups derived from pyridine, pyrimidine, triazine, thiophene, isothiazole, thiazole, pyridazine, pyrrole, pyrazole, imidazole, triazole, thiadiazole, pyrazine, furan, isoxazole, oxazole and the like. Be done. More preferably, it is a group derived from pyridine, pyrimidine, or triazine.

L ² represents a substituted or unsubstituted aromatic heterocyclic group having 3 to 11 carbon atoms, preferably a substituted or unsubstituted aromatic heterocyclic group having 3 to 5 carbon atoms, and more preferably a substituted or unsubstituted aromatic heterocyclic group. It is a nitrogen-containing aromatic group having 3 to 5 carbon atoms.

Specific examples of cases where L ² is an unsubstituted aromatic heterocyclic group include pyridine, pyrimidine, triazine, thiophene, isothiazole, thiazole, pyridazine, pyrrole, pyrazole, imidazole, pyrazine, furan, isothiazole, oxazole, and quinoline. , Isoquinoline, quinoxalin, quinazoline, benzotriazole, phthalazine, indol, benzofuran, benzothiophene, benzoxazole, benzothiazole, indazole, benzimidazole, benzoisothiazole or benzothiaziazole. Preferred include groups resulting from pyridine, pyrimidine, triazine, thiophene, isothiazole, thiazole, pyridazine, pyrrole, pyrazole, imidazole, triazole, thiadiazole, pyrazine, furan, isoxazole, oxazole and the like. More preferably, it is a group derived from pyridine, pyrimidine, or triazine.

L ¹ is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 11 carbon atoms, and preferably substituted or unsubstituted carbon. It is an aromatic hydrocarbon group having a number of 6 to 24, and more preferably an aromatic hydrocarbon group having 6 to 18 carbon atoms which is substituted or unsubstituted. Specific examples when L ¹ is an unsubstituted aromatic hydrocarbon group are the same as in the case of Ar ¹ and Ar ² , and specific examples when L 1 is an unsubstituted aromatic heterocyclic group are L ² and The same is true. Note that L ¹ is a divalent group and L ² is an e + 1 valent group.

Ar ³ represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted linked aromatic group in which 2 to 5 of these aromatic hydrocarbon groups are linked, preferably. It is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 24 carbon atoms, or a substituted or unsubstituted linked aromatic group formed by linking 2 to 5 of these aromatic hydrocarbon groups, and more preferably. It is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or a substituted or unsubstituted linked aromatic group formed by linking 2 to 5 of these aromatic hydrocarbon groups. Specific examples when Ar ³ is an unsubstituted aromatic hydrocarbon group are the same as in the case of Ar ¹ and Ar ² . More preferably, it is a phenyl group, a biphenyl group, or a terphenyl group. The terphenyl group may be linearly linked or branched.

a and b independently represent an integer of 0 to 4, and c represents an integer of 0 to 2. However, a + b + c ≧ 1. Preferably, a and b each independently represent an integer of 0 to 1, and c is preferably 1 or 2. More preferably, at least one of a and b is 0.
d is the number of repetitions, which is an integer of 0 to 3, preferably an integer of 0 to 1, and more preferably 0. e represents the number of substitutions, represents an integer of 0 to 5, preferably 0 to 3, and more preferably 0 to 2.

In the present specification, the unsubstituted aromatic hydrocarbon group, the aromatic heterocyclic group, or the linked aromatic group may each have a substituent. When having a substituent, the substituents are heavy hydrogen, halogen, cyano group, triarylsilyl group, aliphatic hydrocarbon group having 1 to 10 carbon atoms, alkoxy group having 2 to 5 carbon atoms, and 1 to 5 carbon atoms. An alkoxy group or a diarylamino group having 12 to 44 carbon atoms is preferable. Here, when the substituent is an aliphatic hydrocarbon group having 1 to 10 carbon atoms, it may be linear, branched, or cyclic.
The number of substituents is 0 to 5, preferably 0 to 2. When the aromatic hydrocarbon group and the aromatic heterocyclic group have a substituent, the carbon number calculation does not include the carbon number of the substituent. However, it is preferable that the total number of carbon atoms including the number of carbon atoms of the substituent satisfies the above range.

Specific examples of the above substituents include cyano, methyl, ethyl, propyl, i-propyl, butyl, t-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, vinyl, propenyl, butenyl, Examples thereof include pentenyl, methoxy, ethoxy, propoxy, butoxy, pentoxy, diphenylamino, naphthylphenylamino, dinaphthylamino, dianthranylamino, diphenanthrenylamino, dipyrenylamino and the like. Preferred include cyano, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, diphenylamino, naphthylphenylamino, or dinaphthylamino.

In the present specification, the linked aromatic group refers to an aromatic group in which the carbons of the aromatic ring of the aromatic group are linked by a single bond. It is an aromatic group in which two or more aromatic groups are linked, and these may be linear or branched. The aromatic group may be an aromatic hydrocarbon group or an aromatic heterocyclic group, and the plurality of aromatic groups may be the same or different. The aromatic group corresponding to the linked aromatic group is different from the substituted aromatic group.

It is understood herein that hydrogen may be deuterium. That is, in the general formulas (1) to (10) and the like, part or all of H contained in the skeleton such as indolocarbazole and the ^{substituent such as R 1} ^{and Ar 1 may be deuterium.}

As a preferable embodiment of the compound represented by the general formula (1), there is a compound represented by any of the above formulas (2) to (7), and more preferably any of the formulas (2) to (5). It is a compound represented. In the formulas (2) to (7), the symbols common to the general formula (1) have the same meaning.

Specific examples of the compound represented by the general formula (1) are shown below, but the compound is not limited to these exemplified compounds.

The organic electroluminescent device of the present invention has a plurality of organic layers between an anode and a cathode, and at least one of the organic layers contains the above-mentioned material for an organic electroluminescent device.
In another aspect of the organic electroluminescent device of the present invention, at least one of the compounds represented by the general formulas (8) to (10) is contained in the same layer together with the above-mentioned material for an organic electroluminescent device.

In the general formula (8), Ar ⁴ and Ar ⁵ are independently substituted or unsubstituted aromatic hydrocarbon groups having 6 to 30 carbon atoms, and substituted or unsubstituted aromatic heterocycles having 3 to 17 carbon atoms, respectively. A group, or a substituted or unsubstituted linked aromatic group formed by linking 2 to 5 of these aromatic rings, preferably an aromatic hydrocarbon group having 6 to 12 carbon atoms, or an aromatic hydrocarbon group thereof. It shows a substituted or unsubstituted linked aromatic group formed by linking 2 to 4, and more preferably an aromatic hydrocarbon group having 6 to 10 carbon atoms or 2 to 3 linked aromatic hydrocarbon groups thereof. Substituted or unsubstituted linked aromatic groups.

Specific examples when Ar ⁴ and Ar ⁵ are an unsubstituted aromatic hydrocarbon group, an aromatic heterocyclic group, or a linked aromatic group are the same as in the case of Ar ² . Preferably, benzene, naphthalene, or a group formed by taking one hydrogen from a compound composed of 2 to 4 of these linked together can be mentioned. More preferably, it is a phenyl group, a biphenyl group, or a terphenyl group. The terphenyl group may be linearly linked or branched.

Specific examples of the compound represented by the general formula (8) are shown below, but the compound is not limited to these exemplified compounds.

In the general formula (9), the ring B is a heterocycle represented by the formula (9b) or (9c), and the ring B is condensed with an adjacent ring at an arbitrary position.

L ³ is an independently substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, and is preferably substituted or unsubstituted. It is an aromatic hydrocarbon group having 6 to 24 carbon atoms, more preferably a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, and further preferably a phenylene group. Specific examples of the case where L ³ is an unsubstituted aromatic hydrocarbon group or an aromatic heterocyclic group are the same as in the case of Ar ² . L ³ is a divalent group.

X represents NAr ⁸ , O, or S, preferably NAr ⁸ or O, and more preferably NAr ⁸ .

Ar ⁶ , Ar ⁷ , and Ar ⁸ are independently substituted or unsubstituted aromatic hydrocarbon groups having 6 to 30 carbon atoms, substituted or unsubstituted aromatic heterocyclic groups having 3 to 17 carbon atoms, or These aromatic rings are substituted or unsubstituted linked aromatic groups in which 2 to 5 are linked, preferably substituted or unsubstituted aromatic hydrocarbon groups having 6 to 24 carbon atoms, substituted or unsubstituted carbons. It is an aromatic heterocyclic group having a number of 3 to 15, or a substituted or unsubstituted linked aromatic group formed by linking these aromatic rings with 2 to 5, more preferably having 6 to 18 substituted or unsubstituted carbon atoms. Aromatic hydrocarbon groups of the above, or substituted or unsubstituted linked aromatic groups formed by linking 2 to 5 of these aromatic hydrocarbon groups.

Specific examples when Ar ⁶ , Ar ⁷ , and Ar ⁸ are an unsubstituted aromatic hydrocarbon group, an aromatic heterocyclic group, or a linked aromatic group are the same as in the case of Ar ² , and are preferable. , Benzene, naphthalene, acenaphthene, acenaftylene, azulene, anthracene, chrysene, pyrene, phenanthrene, triphenylene, fluorene, benzo [a] anthracene, tetracene, pentacene, hexacene, coronen, heptacente, pyridine, pyrimidine, triazine, thiophene, isothiazole, Thiazol, pyridazine, pyrrol, pyrazole, imidazole, triazole, thiazazole, pyrazine, furan, isoxazole, quinoline, isoquinoline, quinoxalin, quinazoline, thiazizole, phthalazine, tetrazole, indol, benzofuran, benzothiophene, benzoxazole, benzothiazole, indazole, benz. One from imidazole, benzotriazole, benzoisothiazole, benzothiazol, purine, pyranone, coumarin, isocmarin, chromone, dibenzofuran, dibenzothiophene, dibenzoselenophene, carbazole, or a compound composed of 2 to 5 linkages thereof. Examples include groups produced by taking hydrogen. More preferably, one from benzene, naphthalene, acenaphthene, acenaphthylene, azulene, anthracene, chrysene, pyrene, phenanthrene, triphenylene, fluorene, benzo [a] anthracene, tetracene, or a compound composed of 2 to 5 linkages thereof. The group produced by taking hydrogen from fluorene can be mentioned. More preferably, it is a phenyl group, a biphenyl group, or a terphenyl group. The terphenyl group may be linearly linked or branched.

Ar ⁶ preferably has a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 12 to 17 carbon atoms, or an aromatic ring having 2 to 2 to 17 of these aromatic rings. It is a substituted or unsubstituted linked aromatic group consisting of 5 linked aromatic group, more preferably a substituted or unsubstituted aromatic hydrocarbon group having 6 to 24 carbon atoms, and a substituted or unsubstituted aromatic group having 12 to 17 carbon atoms. A group heterocyclic group, or a substituted or unsubstituted linked aromatic group formed by connecting 2 to 5 of these aromatic rings, and more preferably an substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms. , Or a substituted or unsubstituted linked aromatic group formed by linking 2 to 5 of these aromatic hydrocarbon groups.

Specific examples of the case where Ar ⁶ is an unsubstituted aromatic heterocyclic group having 12 to 17 carbon atoms include a group derived from dibenzofuran, dibenzothiophene, dibenzoselenophene, or carbazole.

I and j independently represent integers of 0 to 3, preferably i and j are 0 to 1, more preferably i is 0, and j is 1. However, i + j is an integer of 1 or more.

K and v represent the number of substitutions, k represents 0 to 3, v independently represents an integer of 0 to 4, preferably k and v are 0 to 1, and more preferably k and v are 0.

R ¹ to R ³ are independently cyano groups, alkyl groups having 1 to 20 carbon atoms, aralkyl groups having 7 to 38 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, alkynyl groups having 2 to 20 carbon atoms, and carbon atoms. A dialkylamino group having 2 to 40 carbon atoms, a diarylamino group having 12 to 44 carbon atoms, a dialalkylamino group having 14 to 76 carbon atoms, an acyl group having 2 to 20 carbon atoms, an acyloxy group having 2 to 20 carbon atoms, and a carbon number of carbon atoms. 1 to 20 alkoxy groups, 2 to 20 carbons alkoxycarbonyl groups, 2 to 20 carbons alkoxycarbonyloxy groups, 1 to 20 carbons alkylsulfonyl groups, substituted or unsubstituted aromatics with 6 to 30 carbon atoms A group hydrocarbon group or an aromatic heterocyclic group having 3 to 17 carbon atoms substituted or unsubstituted is shown. It preferably represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 24 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, and more preferably an substituted or unsubstituted aromatic hydrocarbon group. It is an aromatic hydrocarbon group of 6 to 18 or an unsaturated aromatic heterocyclic group having 3 to 12 carbon atoms which is not substituted.

R ¹ to R ³ are an alkyl group having 1 to 20 carbon atoms, an aralkyl group having 7 to 38 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, and a dialkylamino having 2 to 40 carbon atoms. Group, diarylamino group with 12 to 44 carbon atoms, dialalkylamino group with 14 to 76 carbon atoms, acyl group with 2 to 20 carbon atoms, acyloxy group with 2 to 20 carbon atoms, alkoxy group with 1 to 20 carbon atoms, Specific examples of the alkoxycarbonyl group having 2 to 20 carbon atoms, the alkoxycarbonyloxy group having 2 to 20 carbon atoms, and the alkylsulfonyl group having 1 to 20 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, and cyclopentyl. , Hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecil, icosyl and other alkyl groups, phenylmethyl, phenylethyl, phenylicosyl, naphthylmethyl, Aralkyl groups such as anthranylmethyl, phenanthrenylmethyl and pyrenylmethyl, alkenyl groups such as vinyl, propenyl, butenyl, pentenyl, decenyl and icosenyl, alkynyl groups such as ethynyl, propargyl, butynyl, pentynyl, decynyl and icosinyl, dimethylamino, Dialkylamino groups such as ethylmethylamino, diethylamino, dipropylamino, dibutylamino, dipentynylamino, didecylamino, diicosylamino, diphenylamino, naphthylphenylamino, dinaphthylamino, dianthranylamino, diphenanthrenylamino, dipyrenylamino Diarylamino groups such as diarylamino groups, diphenylmethylamino, diphenylethylamino, phenylmethylphenylethylamino, dinaphthylmethylamino, dianthranylmethylamino, diphenolylmethylamino and the like, acetyl, propionyl, butyryl, etc. Acrylic groups such as valeryl and benzoyl, acyloxy groups such as acetyloxy, propionyloxy, butyryloxy, valeryloxy and benzoyloxy, alkoxy groups such as methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy, heptoxy, octoxy, nonyloxy and decanyloxy, methoxy. Alkoxycarbonyl groups such as carbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, pentoxycarbonyl, methoxy Alkoxycarbonyloxy groups such as carbonyloxy, ethoxycarbonyloxy, propoxycarbonyloxy, butoxycarbonyloxy, pentoxycarbonyloxy, alkylsulfoxy groups such as methylsulfonyl, ethylsulfonyl, propylsulfonyl, butylsulfonyl, pentylsulfonyl, cyano groups, Examples thereof include a nitro group, a fluoro group and a tosyl group. Preferred are methyl, ethyl, propyl, butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, or dodecyl.

Specific examples in the case where R ¹ to R ³ are an unsubstituted aromatic hydrocarbon group or an aromatic heterocyclic group are the same as in the case of Ar ² described above. When R ¹ to R ³ are aromatic hydrocarbon groups, the above general formula (1) may also be applicable. In that case, the compound having j of 1 or more in the general formula (9) is generally used. The compounds of formula (9) are treated, and the other compounds are treated as compounds of general formula (1), and are not classified as compounds corresponding to both.

F and h each independently represent an integer of 0 to 4, preferably 0 to 1, and more preferably 0. g represents an integer of 0 to 2, preferably 0 to 1, more preferably 0.

Specific examples of the compound represented by the general formula (9) are shown below, but the compound is not limited to these exemplified compounds.

In the general formula (10), the ring D is a heterocycle represented by the formula (10d), and the ring D is condensed with an adjacent ring at an arbitrary position.

Ar ⁹ independently agrees with ^{Ar 6} of general formula (9).
R ⁴ to R ⁶ independently agree with ^{R 1} to R ³ of the general formula (9).

l and n each independently represent an integer of 0 to 4, preferably 0 to 1, and more preferably 0.
m represents an integer of 0 to 2, preferably 0 to 1, and more preferably 0.

Ar ¹⁰ is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a substituted or unsubstituted aromatic group in which 2 to 5 of them are linked. Represents a substituted linked aromatic group. Preferably, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 24 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 15 carbon atoms, or 2 to 5 of these aromatic rings are linked. Substituted or unsubstituted linked aromatic groups, more preferably substituted or unsubstituted aromatic hydrocarbon groups having 6 to 18 carbon atoms, or substituted or unsubstituted aromatic rings in which these aromatic rings are linked by 2 to 5 It is a linked aromatic group of.

Specific examples of the case where Ar ¹⁰ is an unsubstituted aromatic hydrocarbon group and an unsubstituted aromatic heterocyclic group are the same as in the case of Ar ⁷ and Ar ⁸ . Ar ¹⁰ is a divalent group.

Specific examples of the compound represented by the general formula (10) are shown below, but the compound is not limited to these exemplified compounds.

The material for an organic electroluminescent device of the present invention is contained in an organic layer, and the organic layer includes a light emitting layer, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a hole blocking layer and the like. It may be selected from a herd of electron blocking layers.
It is preferably a light emitting layer, and the light emitting layer may contain at least one kind of light emitting dopant.

When the light emitting layer contains the material for the organic electroluminescent device of the present invention, it is desirable that the light emitting layer is included as a host. Advantageously, the material for an organic electroluminescent device of the present invention is used as a first host, and a compound selected from the compounds represented by the general formulas (8), (9), or (10) is contained as a second host. Is good.

When the above compounds are used as the first host and the second host, these compounds can be individually vapor-deposited from different vapor deposition sources, but they are premixed before vapor deposition for organic EL elements. It is preferable to use a mixed composition (also referred to as a premix) and simultaneously vapor-deposit the premix from one vapor deposition source to form a light emitting layer. In this case, the premix may be mixed with the luminescent dopant material required to form the light emitting layer or other hosts used as needed, but there is a large difference in the temperature at which the desired vapor pressure is obtained. In that case, it is preferable to vapor-deposit from another vapor deposition source.

The mixed composition of the present invention contains a compound represented by the above general formula (1) and a compound represented by any of the general formulas (8) to (10). One type of these compounds may be used, or two or more types may be used. Preferably, the compound represented by the general formula (1) and the compound represented by the general formula (8) are included. It is desirable that each compound blended in the mixed composition has a 50% weight loss temperature of 20 ° C. or less.

Further, as for the mixing ratio (weight ratio) of the first host and the second host, the ratio of the first host to the total of the first host and the second host is preferably 10 to 70%, preferably more than 15%. , Less than 65%, more preferably 20-60%.

Next, the structure of the organic EL element of the present invention will be described with reference to the drawings, but the structure of the organic EL element of the present invention is not limited to this.

FIG. 1 is a cross-sectional view showing a structural example of a general organic EL device used in the present invention, in which 1 is a substrate, 2 is an anode, 3 is a hole injection layer, 4 is a hole transport layer, and 5 is a light emitting layer. , 6 represent an electron transport layer, and 7 represents a cathode. The organic EL device of the present invention may have an exciton blocking layer adjacent to the light emitting layer, or may have an electron blocking layer between the light emitting layer and the hole injection layer. The exciton blocking layer can be inserted into either the cathode side or the cathode side of the light emitting layer, and both can be inserted at the same time. The organic EL device of the present invention has an anode, a light emitting layer, and a cathode as essential layers, but it is preferable to have a hole injection transport layer and an electron injection transport layer in addition to the essential layers, and further, a light emitting layer and an electron injection. It is preferable to have a hole blocking layer between the transport layers. The hole injection transport layer means either or both of the hole injection layer and the hole transport layer, and the electron injection transport layer means either or both of the electron injection layer and the electron transport layer.

The structure opposite to that of FIG. 1, that is, the cathode 7, the electron transport layer 6, the light emitting layer 5, the hole transport layer 4, and the anode 2 can be laminated in this order on the substrate 1, and in this case as well, the layers can be laminated in this order. It can be added or omitted.

-substrate-
The organic EL device of the present invention is preferably supported by a substrate. The substrate is not particularly limited as long as it is conventionally used for an organic EL element, and for example, a substrate made of glass, transparent plastic, quartz or the like can be used.

-anode-
As the anode material in the organic EL element, a material having a large work function (4 eV or more), an alloy, an electrically conductive compound, or a mixture thereof is preferably used. Specific examples of such electrode materials include metals such as Au, and conductive transparent materials such as _{CuI, indium tin oxide (ITO), SnO 2, and ZnO.} Further, an amorphous material such as IDIXO (In ₂ O _3- ZnO) capable of producing a transparent conductive film may be used. For the anode, a thin film may be formed by forming a thin film of these electrode materials by a method such as thin film deposition or sputtering, and a pattern of a desired shape may be formed by a photolithography method, or when pattern accuracy is not required so much (about 100 μm or more). May form a pattern through a mask having a desired shape during vapor deposition or sputtering of the electrode material. Alternatively, when a coatable substance such as an organic conductive compound is used, a wet film forming method such as a printing method or a coating method can also be used. When light emission is taken out from this anode, it is desirable to increase the transmittance to more than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. The film thickness depends on the material, but is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.

-cathode-
On the other hand, as the cathode material, a material having a small work function (4 eV or less) (electron-injectable metal), an alloy, an electrically conductive compound, or a mixture thereof is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O). ₃ ) Examples include mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, from the viewpoint of electron injectability and durability against oxidation, etc., a mixture of an electron injectable metal and a second metal which is a stable metal having a larger work function value than this, for example, magnesium / silver mixture, magnesium / Aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide mixture, lithium / aluminum mixture, aluminum and the like are suitable. The cathode can be produced by forming a thin film of these cathode materials by a method such as vapor deposition or sputtering. The sheet resistance of the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 to 200 nm. In order to transmit the emitted light, if either the anode or the cathode of the organic EL element is transparent or translucent, the emission brightness is improved, which is convenient.

Further, by forming the above metal on the cathode with a thickness of 1 to 20 nm and then forming the conductive transparent material mentioned in the description of the anode on the cathode, a transparent or translucent cathode can be produced. By applying this, it is possible to manufacture an element in which both the anode and the cathode are transparent.

-Light emitting layer-
The light emitting layer is a layer that emits light after excitons are generated by recombination of holes and electrons injected from each of the anode and cathode, and the light emitting layer may contain an organic light emitting dopant material and a host. ..

As the host, the first host and the second host may be used.
As the compound represented by the general formula (1) as the first host, one kind may be used, or two or more kinds may be used. Similarly, one kind of carbazole compound or indolocarbazole compound represented by the general formulas (8) to (10) as the second host may be used, or two or more kinds may be used.
If necessary, one or a plurality of other known host materials may be used in combination, but the amount used may be 50 wt% or less, preferably 25 wt% or less, based on the total amount of the host materials.

The form of the host and its premixture may be powder, stick or granular.

When using multiple types of hosts, each host can be vapor-deposited from different vapor deposition sources, or multiple types of hosts can be vapor-deposited from one vapor deposition source at the same time by premixing them before vapor deposition to form a premixture. ..

As a method of premixing, a method capable of mixing as uniformly as possible is desirable, and examples thereof include pulverization mixing, heating and melting under reduced pressure or in an atmosphere of an inert gas such as nitrogen, sublimation, and the like. It is not limited to the method.

When the first host and the second host are premixed and used, it is desirable that the difference _{in the 50% weight loss temperature (T 50} ) is small in order to produce an organic EL device having good characteristics with good reproducibility. .. The 50% weight loss temperature is the temperature at which the weight is reduced by 50% when the temperature is raised from room temperature to 550 ° C at a rate of 10 ° C per minute in TG-DTA measurement under nitrogen airflow decompression (1 Pa). .. It is considered that vaporization by evaporation or sublimation occurs most actively in the vicinity of this temperature.

The difference between the 50% weight loss temperature of the first host and the second host is preferably within 20 ° C, more preferably within 15 ° C. As the premixing method, a known method such as pulverization and mixing can be adopted, but it is desirable to mix as uniformly as possible.

When a phosphorescent dopant is used as the luminescent dopant material, the phosphorescent dopant contains an organic metal complex containing at least one metal selected from ruthenium, rhodium, palladium, silver, renium, osmium, iridium, platinum and gold. What to do is good. Specifically, the iridium complexes described in J.Am.Chem.Soc.2001,123,4304 and JP-A-2013-53051 are preferably used, but are not limited thereto.

As the phosphorescent dopant material, only one type may be contained in the light emitting layer, or two or more types may be contained. The content of the phosphorescent dopant material is preferably 0.1 to 30 wt% and more preferably 1 to 20 wt% with respect to the host material.

The phosphorescent dopant material is not particularly limited, but specific examples include the following.

When a fluorescent light emitting dopant is used as the light emitting dopant material, the fluorescent light emitting dopant is not particularly limited, and is, for example, a benzoxazole derivative, a benzothiazole derivative, a benzoimidazole derivative, a styrylbenzene derivative, a polyphenyl derivative, a diphenylbutadiene derivative, or a tetraphenyl. Butadiene derivative, naphthalimide derivative, coumarin derivative, condensed aromatic compound, perinone derivative, oxadiazole derivative, oxazine derivative, aldazine derivative, pyrrolidine derivative, cyclopentadiene derivative, bisstyrylanthracene derivative, quinacridone derivative, pyrolopyridine derivative, thiasia Polythiophene, such as zolopyridine derivatives, styrylamine derivatives, diketopyrrolopyrrole derivatives, aromatic dimethyridine compounds, metal complexes of 8-quinolinol derivatives, metal complexes of pyromethene derivatives, rare earth complexes, various metal complexes typified by transition metal complexes, etc. Examples thereof include polymer compounds such as polyphenylene and polyphenylene vinylene, and organic silane derivatives. Preferred are condensed aromatic derivatives, styryl derivatives, diketopyrrolopyrrole derivatives, oxazine derivatives, pyromethene metal complexes, transition metal complexes, or lanthanoid complexes, and more preferably naphthalene, pyrene, chrysene, triphenylene, benzo [c] phenanthrene. , Benzo [a] anthracene, pentacene, perylene, fluorantene, acenafusofluoranthen, dibenzo [a, j] anthracene, dibenzo [a, h] anthracene, benzo [a] naphthalene, hexacene, naphtho [2,1-f] ] Isoquinoline, α-naphthaphenanthridin, phenanthrooxazole, quinolino [6,5-f] quinoline, benzothiophantrene and the like can be mentioned. These may have an alkyl group, an aryl group, an aromatic heterocyclic group, or a diarylamino group as a substituent.

As the fluorescent light emitting dopant material, only one kind may be contained in the light emitting layer, or two or more kinds may be contained. The content of the fluorescent dopant material is preferably 0.1 to 20%, more preferably 1 to 10% with respect to the host material.

When a heat-activated delayed fluorescence light-emitting dopant is used as the light-emitting dopant material, the heat-activated delayed fluorescence light-emitting dopant is not particularly limited, but is described in a metal complex such as a tin complex or a copper complex, or as described in WO2011 / 070963. Indrocarbazole derivatives, cyanobenzene derivatives described in Nature 2012,492,234, carbazole derivatives, phenazine derivatives described in Nature Photonics 2014,8,326, oxaziazole derivatives, triazole derivatives, sulfone derivatives, phenoxazine derivatives, acrydin derivatives and the like. Be done.

The thermally activated delayed fluorescence dopant material is not particularly limited, but specific examples include the following.

The thermally activated delayed fluorescent dopant material may contain only one type or two or more types in the light emitting layer. Further, the thermally activated delayed fluorescence dopant may be mixed with a phosphorescence light emitting dopant or a fluorescence emission dopant. The content of the thermally activated delayed fluorescent dopant material is preferably 0.1 to 50%, more preferably 1 to 30% with respect to the host material.

-Injection layer-
The injection layer is a layer provided between the electrode and the organic layer in order to reduce the driving voltage and improve the emission brightness. There are a hole injection layer and an electron injection layer, and between the anode and the light emitting layer or the hole transport layer, And may be present between the cathode and the light emitting layer or the electron transporting layer. The injection layer can be provided as needed.

-Hole blocking layer-
The hole blocking layer has the function of an electron transporting layer in a broad sense, and is made of a hole blocking material having a function of transporting electrons and a significantly small ability to transport holes. By blocking the above, the recombination probability of electrons and holes in the light emitting layer can be improved.

A known hole blocking layer material can be used for the hole blocking layer, but it is preferable to contain a compound represented by the general formula (1).

-Electronic blocking layer-
The electron blocking layer has a function of a hole transporting layer in a broad sense, and by blocking electrons while transporting holes, the probability of recombination of electrons and holes in the light emitting layer can be improved. ..

As the material of the electron blocking layer, a known electron blocking layer material can be used, and a hole transporting layer material described later can be used as needed. The film thickness of the electron blocking layer is preferably 3 to 100 nm, more preferably 5 to 30 nm.

-Exciton blocking layer-
The exciton blocking layer is a layer for preventing excitons generated by recombination of holes and electrons in the light emitting layer from diffusing into the charge transport layer, and the excitons are inserted by inserting this layer. It is possible to efficiently confine it in the light emitting layer, and it is possible to improve the light emitting efficiency of the element. The exciton blocking layer can be inserted between two adjacent light emitting layers in an element in which two or more light emitting layers are adjacent to each other.

As the material of the exciton blocking layer, a known exciton blocking layer material can be used. For example, 1,3-dicarbazolylbenzene (mCP) and bis (2-methyl-8-quinolinolato) -4-phenylphenylatoaluminum (III) (BAlq) can be mentioned.

-Hole transport layer-
The hole transport layer is made of a hole transport material having a function of transporting holes, and the hole transport layer may be provided as a single layer or a plurality of layers.

The hole transport material has any of hole injection or transport and electron barrier property, and may be either an organic substance or an inorganic substance. Any compound can be selected and used for the hole transport layer from conventionally known compounds. Examples of such hole transporting materials include porphyrin derivatives, arylamine derivatives, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, and amino-substituted chalcone derivatives. , Oxazole derivative, styrylanthracene derivative, fluorenone derivative, hydrazone derivative, stilben derivative, silazane derivative, aniline-based copolymer, and conductive polymer oligomer, especially thiophene oligomer. It is preferable to use an amine derivative, and it is more preferable to use an arylamine compound.

-Electron transport layer-
The electron transport layer is made of a material having a function of transporting electrons, and the electron transport layer may be provided with a single layer or a plurality of layers.

The electron transporting material (which may also serve as a hole blocking material) may have a function of transmitting electrons injected from the cathode to the light emitting layer. For the electron transport layer, any of conventionally known compounds can be selected and used. For example, polycyclic aromatic derivatives such as naphthalene, anthracene and phenanthroline, tris (8-quinolinolato) aluminum (III). Derivatives, phosphine oxide derivatives, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, carbodiimides, fraolenilidene methane derivatives, anthracinodimethane and anthracene derivatives, bipyridine derivatives, quinoline derivatives, oxadiazole derivatives, benzoimidazole Derivatives, benzothiazole derivatives, indolocarbazole derivatives and the like can be mentioned, and polymer materials in which these materials are introduced into a polymer chain or these materials are used as the main chain of a polymer can also be used.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples, and can be carried out in various forms as long as the gist thereof is not exceeded.

Synthesis example 1
Compound 129 was synthesized according to the following reaction formula.

Under a nitrogen atmosphere, 10.0 g (13.9 mmol) of the intermediate (a), 2.2 g (18.1 mmol) of the compound (b), 0.5 g (0.4 mmol) of tetrakis (triphenylphosphine) palladium (0), and 5.8 g of potassium carbonate. , M-xylene 300 ml, ethanol 30 ml, distilled water 30 ml were added, and the mixture was stirred for 3 hours while heating at 100 ° C. After cooling to room temperature, distilled water (50 ml) was added, the organic layer was separated, and the mixture was concentrated to dryness. The obtained solid was purified by silica gel column chromatography and crystallized to obtain 5.3 g (7.4 mmol, yield 53.2%) of compound 129 as a yellow solid (APCI-TOFMS, m / z 716 [M + H). ] ⁺ ).

Synthesis example 2

Under a nitrogen atmosphere, the intermediate (c) was 10.0 g (24.2 mmol), the compound (d) was 6.2 g (50.7 mmol), tetrakis (triphenylphosphine) palladium (0) was 0.8 g (0.7 mmol), and potassium carbonate was 10.0 g. , M-xylene 300 ml, ethanol 30 ml, distilled water 30 ml were added, and the mixture was stirred for 3 hours while heating at 100 ° C. After cooling to room temperature, distilled water (200 ml) was added, and the precipitated solid was collected by filtration. The obtained solid was crystallized and purified to obtain 5.5 g (13.4 mmol, yield 55.8%) of the intermediate (f) (APCI-TOFMS, m / z 409 [M + H] ⁺ ).

Synthesis example 3

Under a nitrogen atmosphere, the intermediate (f) was 10.0 g (24.5 mmol), the compound (g) was 7.5 g (36.7 mmol), CuI was 0.9 g (4.9 mmol), and tripotassium phosphate was 26.0 g (120.0 mmmol). , 300 ml of 1,4-dioxane and 1.1 g (9.8 mmol) of trans-1,2-cyclohexanediamine were added, and the mixture was stirred under heating and reflux for 6 hours. After cooling to room temperature, the liquid layer obtained by solid-liquid separation was concentrated to dryness.
The obtained solid was purified by silica gel column chromatography to obtain 5.2 g (10.7 mmol, yield 43.8%) of the intermediate (h) (APCI-TOFMS, m / z 485 [M + H] ⁺ ).

Synthesis example 4

Under a nitrogen atmosphere, 1.0 g (24.8 mmol) of 60 wt% sodium hydride was added to 200 g of N, N'-dimethylacetamide to prepare a suspension. 10.0 g (20.6 mmol) of the intermediate (h) was added thereto, and the mixture was stirred for 1 hour and then cooled to 5 ° C. After adding 9.2 g (26.8 mmol) of compound (j) to the mixture, the mixture was returned to room temperature and stirred for 4 hours. The reaction solution was added to a mixed solution of ethanol (100 ml) and distilled water (200 ml) with stirring, and the precipitated solid was collected by filtration. The obtained solid was purified by silica gel column chromatography and crystallized to obtain 7.1 g (9.0 mmol, yield 43.4%) of compound 120 as a yellow solid (APCI-TOFMS, m / z 792 [M + H). ] ⁺ ).

Compounds 128, 155, 112, 122 and 156 were synthesized according to the above synthesis example. In addition, compounds A, B, C, D and E for comparison were synthesized.

Example 1
Each thin film was laminated with a ^{vacuum degree of 4.0 × 10 -5} Pa by a vacuum vapor deposition method on a glass substrate on which an anode made of ITO having a film thickness of 110 nm was formed. First, CuPc was formed on the ITO to a thickness of 25 nm as a hole injection layer, and then NPD was formed to a thickness of 30 nm as a hole transport layer. Next, HT-1 was formed to a thickness of 10 nm as an electron blocking layer. Next, compound 128 as a host material and Ir (ppy) ₃ as a light emitting dopant were co-deposited from different vapor deposition sources to form a light emitting layer with a thickness of 40 nm. At this time, _{the concentration of Ir (ppy) 3} was 10 wt%. Furthermore, H-3 was formed to a thickness of 10 nm as a hole blocking layer. Next, ET-1 was formed to a thickness of 10 nm as an electron transport layer. Further, LiF was formed on the electron transport layer as an electron injection layer to a thickness of 1 nm. Finally, Al was formed as a cathode on the electron injection layer to a thickness of 70 nm to prepare an organic EL device.
When an external power source was connected to the obtained organic EL element and a DC voltage was applied, an emission spectrum with a maximum wavelength of 517 nm was observed, and it was found that emission from _{Ir (ppy) 3 was obtained.}

Examples 2-7
An organic EL device was prepared in the same manner as in Example 1 except that compounds 155, 112, 120, 122, 129, or 156 were used instead of compound 128 as the host material for the light emitting layer in Example 1. When a DC voltage was applied to the obtained organic EL device, an emission spectrum with a maximum wavelength of 517 nm was observed.

Comparative Examples 1 to 4
An organic EL device was produced in the same manner as in Example 1 except that compound A, B, C, or D was used as the host material for the light emitting layer in Example 1. When an external power source was connected to the obtained organic EL element and a DC voltage was applied, an emission spectrum having a maximum wavelength of 517 nm was observed.

Table 1 shows the evaluation results of the produced organic EL device. In the table, the brightness, drive voltage, and luminous efficiency are ^{the values when the drive current is 20 mA / cm 2} and are the initial characteristics. LT70 is the time required for the initial brightness to decay to 70%, and represents the life characteristic.

Example 8
Each thin film was laminated with a ^{vacuum degree of 4.0 × 10 -5} Pa by a vacuum vapor deposition method on a glass substrate on which an anode made of ITO having a film thickness of 110 nm was formed. First, HAT-CN was formed on the ITO to a thickness of 25 nm as a hole injection layer, and then NPD was formed to a thickness of 30 nm as a hole transport layer. Next, HT-1 was formed to a thickness of 10 nm as an electron blocking layer. Next, compound 128 as the first host, compound 602 as the second host, and Ir (ppy) ₃ as the light emitting dopant were co-deposited from different vapor deposition sources to form a light emitting layer having a thickness of 40 nm. At this time, _{co-deposited under the vapor deposition conditions where the concentration of Ir (ppy) 3} was 10 wt% and the weight ratio between the first host and the second host was 30:70. Next, ET-1 was formed to a thickness of 20 nm as an electron transport layer. Further, LiF was formed on the electron transport layer as an electron injection layer to a thickness of 1 nm. Finally, Al was formed as a cathode on the electron injection layer to a thickness of 70 nm to prepare an organic EL device.

Examples 9-14, 22-48
In Example 8, an organic EL device was produced in the same manner as in Example 8 except that the compounds shown in Table 2 were used as the first host and the second host.

Examples 15-21
Example 8 except that the compounds shown in Table 2 were used for the first host and the second host and co-deposited under the vapor deposition conditions where the weight ratio of the first host and the second host was 40:60. An organic EL element was manufactured in the same manner as in the above.

Examples 49-51
Organic as in Example 8 except that the premix obtained by weighing the first host (0.30 g) and the second host (0.70 g) and mixing them while grinding in a mortar was co-deposited from one vapor deposition source. I made an EL element.

Comparative Examples 6-10, 16-18
In Example 8, an organic EL device was produced in the same manner as in Example 8 except that the compounds shown in Table 2 were used as the first host and the second host.

Comparative Examples 11 to 15
In Example 15, an organic EL device was produced in the same manner as in Example 15 except that the compounds shown in Table 2 were used as the first host and the second host.

Tables 2 and 3 show the evaluation results of the manufactured organic EL device. The brightness, drive voltage, luminous efficiency, and LT70 in the table are the same as those in Table 1.

The compounds used in the examples are shown below.

Table 4 lists the 50% weight loss temperatures (T ₅₀ ) for compounds 112, 120, 129, 602 and 640.

Claims

A material for an organic electroluminescent device composed of a compound represented by the general formula (1).

Here, ring A is a heterocycle represented by the formula (1a), and ring A is condensed with an adjacent ring at an arbitrary position.
Ar 1 is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 11 carbon atoms, or 2 to 5 of these aromatic rings linked together. Indicates a substituted or unsubstituted linked aromatic group consisting of
Ar 2 independently contains a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or these aromatic rings having 2 to 5 carbon atoms. Indicates a substituted or unsubstituted linked aromatic group formed by linking the pieces.
L 1 is independently a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 11 carbon atoms.
L 2 represents a substituted or unsubstituted aromatic heterocyclic group having 3 to 11 carbon atoms.
Ar 3 independently represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted linked aromatic group in which 2 to 5 of the aromatic hydrocarbon groups are linked.
a and b independently indicate an integer of 0 to 4, and c indicates an integer of 0 to 2. However, a + b + c ≧ 1.
d represents the number of repetitions and represents an integer of 0 to 3, and e represents the number of substitutions and represents an integer of 0 to 5.
The material for an organic electroluminescent element according to claim 1, wherein L 2 is a substituted or unsubstituted aromatic heterocyclic group having 3 to 5 carbon atoms.
The Ar 1 , Ar 2 , and L 1 are independently substituted or unsubstituted aromatic hydrocarbon groups having 6 to 24 carbon atoms, or substitutions or substitutions formed by linking 2 to 5 aromatic hydrocarbon groups. The material for an organic electric field light emitting element according to claim 1 or 2, which is an unsubstituted linked aromatic group.
The material for an organic electroluminescent device according to any one of claims 1 to 3, wherein d is 0.
The material for an organic electroluminescent device according to claim 4, wherein the compound represented by the general formula (1) is a compound represented by any of the following formulas (2) to (7).

Here, L 2 , Ar 1 , Ar 2 , Ar 3 , a, b, c and e agree with the above general formula (1).
The material for an organic electroluminescent device according to any one of claims 1 to 5, wherein at least one of a and b is 0.
The material for an organic electroluminescent device according to any one of claims 1 to 6, wherein c is 1 or 2.
An organic electroluminescent device having a plurality of organic layers between an anode and a cathode, and at least one of the organic layers contains the material for an organic electroluminescent device according to any one of claims 1 to 7. An organic electroluminescent device characterized by.
The organic electroluminescent device according to claim 8, wherein at least one of the compounds represented by the following general formulas (8) to (10) is contained in the same layer together with the material for the organic electroluminescent device.

Here, Ar 4 and Ar 5 are independently substituted or unsubstituted aromatic hydrocarbon groups having 6 to 30 carbon atoms, substituted or unsubstituted aromatic heterocyclic groups having 3 to 17 carbon atoms, or these. Indicates a substituted or unsubstituted linked aromatic group formed by linking 2 to 5 aromatic rings.

Here, ring B is a heterocycle represented by the formula (9b) or (9c), and ring B is condensed with an adjacent ring at an arbitrary position.
L 3 is an independently substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms.
X represents NA 8 , O, or S.
Ar 6 , Ar 7 , and Ar 8 are independently substituted or unsubstituted aromatic hydrocarbon groups having 6 to 30 carbon atoms, substituted or unsubstituted aromatic heterocyclic groups having 3 to 17 carbon atoms, or Indicates a substituted or unsubstituted linked aromatic group formed by linking 2 to 5 of these aromatic rings.
i and j each independently represent an integer of 0 to 3, k and v represent the number of substitutions, k represents 0 to 3, and v independently represents an integer of 0 to 4. However, i + j is an integer of 1 or more.
R 1 to R 3 are independently cyano groups, alkyl groups having 1 to 20 carbon atoms, aralkyl groups having 7 to 38 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, alkynyl groups having 2 to 20 carbon atoms, and carbon atoms. A dialkylamino group having 2 to 40 carbon atoms, a diarylamino group having 12 to 44 carbon atoms, a dialalkylamino group having 14 to 76 carbon atoms, an acyl group having 2 to 20 carbon atoms, an acyloxy group having 2 to 20 carbon atoms, and a carbon number of carbon atoms. 1 to 20 alkoxy groups, 2 to 20 carbons alkoxycarbonyl groups, 2 to 20 carbons alkoxycarbonyloxy groups, 1 to 20 carbons alkylsulfonyl groups, substituted or unsubstituted aromatics with 6 to 30 carbon atoms Shows a group hydrocarbon group or an aromatic heterocyclic group having 3 to 17 carbon atoms substituted or unsubstituted.
f and h independently represent an integer of 0 to 4, and g represents an integer of 0 to 2.

Here, the rings D and D'are heterocycles represented by the formula (10d), and the rings D and D'are independently fused with the adjacent rings at arbitrary positions.
Ar 9 independently agrees with Ar 6 of the above general formula (9).
R 4 to R 6 independently agree with R 1 to R 3 of the above general formula (9).
l and n independently represent an integer of 0 to 4, and m independently represents an integer of 0 to 2.
Ar 10 is composed of a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or 2 to 5 of these aromatic rings linked together. Represents a substituted or unsubstituted linked aromatic group.
The organic layer containing the material for the organic electroluminescent element is selected from a group consisting of a light emitting layer, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a hole blocking layer and an electron blocking layer. The organic electroluminescent element according to claim 8 or 9, which is one layer.
The organic electroluminescent element according to claim 10, wherein the organic layer containing the material for the organic electroluminescent element is a light emitting layer, and the light emitting layer contains at least one kind of luminescent dopant.
In producing the organic electroluminescent element according to claim 9 or 10, a mixed composition containing the material for the organic electroluminescent element and at least one of the compounds represented by the general formulas (8) to (10). A method for manufacturing an organic electroluminescent element, which comprises preparing an object and producing a light emitting layer using the object.
Of the mixed composition used in the method for producing an organic electroluminescent device according to claim 12, the material for an organic electroluminescent device and the compounds represented by the general formulas (8) to (10). A mixed composition comprising at least one.
The difference in 50% weight loss temperature between the material for an organic electroluminescent device and the compound represented by the general formula (8), the general formula (9), or the general formula (10) is within 20 ° C. The mixed composition according to claim 13.
The mixed composition according to claim 13 or 14, which comprises the material for an organic electroluminescent device and the compound represented by the general formula (8).